java.lang.ClassCastException: java.lang.Character cannot be cast to java.lang.String

转载自：http://blog.csdn.net/yejin191258966/article/details/8038782

 

这个问题因为我在今天使用iterator迭代输出值得时候，发现使用单字符的

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<table border="1" width="300">      
<s:iterator var="bb" value="{  
    '1','2','3','4','5'  
}">  
    <tr>  
        <td><s:property value="bb"/></td>  
    </tr>       
</s:iterator>  

<table border="1" width="300">
<s:iterator var="bb" value="{
'1','2','3','4','5'
}">
<tr>
<td><s:property value="bb"/></td>
</tr>
</s:iterator>

java.lang.ClassCastException: java.lang.Character cannot be cast to java.lang.String

 at org.apache.struts2.components.Property.start(Property.java:159)

 at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:53)

 at org.apache.jsp.s_002diterator_002dlist_jsp._jspx_meth_s_005fproperty_005f0(s_002diterator_002dlist_jsp.java:173)

 at org.apache.jsp.s_002diterator_002dlist_jsp._jspx_meth_s_005fiterator_005f0(s_002diterator_002dlist_jsp.java:142)

 at org.apache.jsp.s_002diterator_002dlist_jsp._jspService(s_002diterator_002dlist_jsp.java:80)

 at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

 at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

 at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)

 at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)

 at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)

 at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

 at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:426)

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)

 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)

 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)

 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

 at java.lang.Thread.run(Thread.java:722)

如果我们写数组元素时使用的单字符比如：a、b、c、d、e、f、g这样的单字符系统会当做字符处理所以不能这样

解决的办法：

1、使用双引号，外层改成单引号

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<s:iterator var="bb" value='{  
    "1","2","3"  
}'>  
    <tr>  
        <td><s:property value="bb"/></td>  
    </tr>       
</s:iterator>  

<s:iterator var="bb" value='{
"1","2","3"
}'>
<tr>
<td><s:property value="bb"/></td>
</tr>
</s:iterator>

2、在现实内容哪里value变量对象+#

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<s:iterator var="bb" value="{  
    'a','b'  
}">  
    <tr>  
        <td><s:property value="#bb"/></td>  
    </tr>       
</s:iterator>  

<s:iterator var="bb" value="{
'a','b'
}">
<tr>
<td><s:property value="#bb"/></td>
</tr>
</s:iterator>

3、使用系统默认

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<s:iterator var="bb" value="{  
        'a','b'  
    }">  
        <tr>  
            <td><s:property/></td>  
        </tr>       
    </s:iterator>  

<s:iterator var="bb" value="{
'a','b'
}">
<tr>
<td><s:property/></td>
</tr>
</s:iterator>

参考网址：

http://blog.csdn.net/chch010520/article/details/7423143